Today heat exchangers are used as standard equipment for efficient heating or cooling, heat recovery, condensation and evaporation in many fields. Heat exchangers may be of different types and designs, which will depend on what type of medium is to be heated or cooled.
The efficiency of the heat exchanger, i.e., its ability to transfer heat between the two media that are to be “heat exchanged”, will be highly dependent on how clean the surface of the barrier separating the two media is. In many heat exchanger applications, the media employed, for example, seawater, will cause a soiling of the barrier surface owing to biological fouling, deposits, physical particles or the like, this soiling of the barrier surface substantially reducing the efficiency of the heat exchanger over time. This will mean that after being in use for some time, the heat exchanger will, when the heat transfer capacity approaches a specific minimum level, have to be dismantled for cleaning.
In the marine business or industry, heat exchangers are used for cooling, inter alia, the propulsion machinery of a vessel etc., where seawater is used as “cooling medium”. Here, the cleaning of heat exchangers will be both critical and absolutely essential in order to maintain the vessel's required propulsive power.
Today the most common heat exchangers in the marine industry are plate heat exchangers. Heat exchangers of this type are efficient and reliable, but will be difficult and complicated to clean. Such a plate heat exchanger comprises a plate package, which plate package typically comprises a large number of individual plates and a corresponding number of gasket elements, for example, 50-150 plates and a corresponding number of gasket elements, where the individual plates in the plate heat exchanger are assembled to form the plate package. When a heat exchanger of this kind is to be cleaned, it is normally necessary to dismantle the whole plate package, whereby all the plates in the plate package must then be cleaned one at a time, and the same number of gasket elements must either be cleaned or replaced. Dismantling, cleaning and assembly of the said size of heat exchanger is considered to be a full day's job for two people, and represents a substantial cost because of time consumed and use of parts (replacement of gasket elements etc.). The complexity of the cleaning process will mean that there is greater dependence on both available competence and an adequate window of time in order to be able to carry out the cleaning. A lack of available competence and/or window of time will be usual and, as a result, such jobs are increasingly being put in the hands of external companies, which makes this process even more costly, or which also means that the vessel has an enforced period out of service with consequential loss of income.
The modular system for heat exchange between fluids and the open element for heat exchange between fluids in the modular system according to the present disclosure cover the same range of applications as the plate heat exchangers described above, but are provided with a particular view to simplifying the maintenance of the heat exchanger. Requirements as to special competence and/or a larger window of time are virtually eliminated. According to the present disclosure, the modular system will comprise a plurality of open elements, for example, 2-7 open elements, and a corresponding number of individual gaskets. Dismantling, cleaning and assembly are reckoned to be a job of about one hour for one man. Moreover, time consumed and replacement of gasket parts are so reduced as to become insignificant. Furthermore, the actual cleaning process will be so simple that all vessels will have available competence for carrying out this process, and can therefore maintain full control of the cooling capacity of the heat exchanger and thus also critical propulsive power.
WO 95/30867 A1 and NO 316475 B1 describe heat exchanger elements and the manufacture thereof, where it is known that the heat exchanger elements consist of a plate that is folded to form a plurality of slits, where the plate delimits the fluid to be heat exchanged, each fluid flowing in slits on either side of the plate.
EP 909 928 A1 relates to a heat exchanger unit that is used in connection with heat recovery in a building or house, where a plurality of folded plates are provided in a housing, so as to form the heat exchanger unit.
GB 512 689, US 2004/0206486 A1 and US 2009/0229804 A1 teach additional embodiments of heat exchangers and heat exchanger elements.
A common feature of the aforementioned documents is that they do not teach a modular system for heat exchange between fluids, where dismantling/assembly, cleaning and/or maintenance of the modular system has been simplified.